Also known as Turnera diffusa, Damiana is a low-growing plant with yellow flowers and fragrant leaves. It’s native to the subtropical climates of southern Texas, Mexico, Central and South America, and the Caribbean. It’s been used as a medicine since the Mayans walked the earth. Damiana has been used for centuries as an aphrodisiac and bladder tonic because it promotes oxygen supply and increases blood flow and nerve impulses to your penis. This is a VERY good thing.